Which of the following is NOT a daily air compressor check?

• A. Oil level
• B. Hydraulic fluid level
• C. Filters
• D. Leaks

Answer: (B)

Daily checks on an air compressor focus on what keeps the air system clean, cool, and able to deliver steady pressure. Checking the oil level (when the unit is oil-lubricated) ensures proper lubrication, helping to prevent overheating and excessive wear. Inspecting the filters is essential to keep dust and contaminants from entering the compressor and the air lines, which protects components and the quality of the delivered air. Looking for leaks around hoses, fittings, and condensate drains helps maintain system pressure and prevents unsafe conditions or wasted compressed air.

Hydraulic fluid level, on the other hand, belongs to a different system—the hydraulic power side of equipment. That’s not part of the daily air compressor checks, so it’s maintained separately according to hydraulic system procedures. If a unit combines air and hydraulic functions, follow the specific maintenance guidelines for the hydraulic portion, but in standard daily checks for an air compressor, hydraulic fluid level isn’t included.